When you think about age-proofing your brain, what’s the first thing that springs to mind? Eating healthier food, exercising more, and quitting bad habits (i.e., smoking or drinking too much) are all on our list, but when we put the question to neurologist and psychologist, Dan Engle, MD, he surprised us with his answer: “It’s essential that people laugh more,” he said. “Cortisol is a stress hormone that is associated with anxiety and kills brain cells, especially in the hippocampus where memory is stored and recalled.” Wait, stress literally kills brain cells? Yep. According to Engle exposure to chronic stress destroys neurons and reduces neuro-cell function and performance over time.

“Here’s the bottom-line: Laugh more, have more fun, and keep learning throughout your life for a happy, healthy brain,” he urged. Of course, eating well and looking after your body and mind is also important to boosting your long-term memory health and brain function. Ahead, Engle shares his top foods that not only improve your memory but provide a host of other holistic benefits including enhanced cognitive function such as optimal attention span, concentration, organizing, planning, multitasking, and mood.

MYDOMAINE: When should we start thinking about eating for our brain health and why?

DAN ENGEL: The best way to answer this question is through an analogy; when is the best time to plant a fruit tree? 20 years ago. For the purpose of this article, the answer is today. Now is the time to start eating these brain-optimizing foods. Most people wait until there’s actually a health challenge to begin changing their diet, but the reality is that once there’s a problem, it becomes much more difficult to rebalance your body. It’s better to start early and potentially avoid the issue altogether or heighten your body’s ability to course-correct on its own.

There is increasing anecdotal evidence, in our culture today, supported by literature, indicating that noticeable cognitive decline is happening at earlier ages, and this is due to “diseases of excess” defined by having access to too much food, too little movement, and experiencing a general lack of vitality. Brain aging is a fact of life, and while this may be the case, it is possible to slow the process and optimize brain performance.

A University of Virginia study indicates that a decline in cognitive function may be happening as early as our late 20s into our 30s, with the average age range being late 30s to early 40s. Our natural potential, genetically-speaking, when we look at traditional cultures with more land-based diets and active lifestyles, is to reach old age with very little cognitive decline. We are designed to be healthy, vital, and engaged with life well into our later years.

MD: What is one surprising thing about memory health that no one knows but should?

DE: Memory health begins in utero. During the second trimester of a woman’s pregnancy, a fetus’s brain and neurological system are already formed and memories start to be created. If a mother-to-be experiences high levels of stress due to war or trauma during pregnancy, her offspring have a higher susceptibility to experiencing anxiety, PTSD, etc. The mother’s stress hormones become part of the baby’s natural wiring and can create a predisposition to a greater sensitivity to stress.